Scheuhammer A M, Templeton D M
Environment Canada, Canadian Wildlife Service, Ottawa, Ontario.
Toxicology. 1990 Jan-Feb;60(1-2):151-9. doi: 10.1016/0300-483x(90)90169-h.
The accumulation of hepatic and renal Cd, Zn, Cu, and metallothionein (MT) was investigated in ringed turtle doves (Streptopelia risoria) chronically exposed to 3 different concentrations of dietary Cd. When only tissue-Cd was considered as an inducer of MT, kidney was found to be 35% as responsive as liver in producing MT. However, when all potentially relevant inducing metals (Cd + Zn + Cu) were taken into account, kidney was found to be 85% as responsive as liver. The greater production of MT/mol Cd in liver was accounted for mainly by a greater co-accumulation of Zn/mol Cd in liver than in kidney. We conclude that the apparent tissue specificity in expression of MT may be overestimated by failure to consider fluctuations in multiple inducers. Variability in tissue-MT concentrations after chronic dietary Cd administration is best accounted for by a consideration of tissue-Cd, -Zn, and -Cu, rather than tissue-Cd alone.
研究了长期暴露于3种不同膳食镉浓度的环颈斑鸠（Streptopelia risoria）肝脏和肾脏中镉、锌、铜及金属硫蛋白（MT）的蓄积情况。当仅将组织镉视为MT的诱导剂时，发现肾脏产生MT的反应性仅为肝脏的35%。然而，当考虑所有潜在相关的诱导金属（镉+锌+铜）时，发现肾脏产生MT的反应性为肝脏的85%。肝脏中每摩尔镉产生的MT更多，这主要是因为肝脏中每摩尔镉的锌共蓄积量比肾脏中更多。我们得出结论，若不考虑多种诱导剂的波动情况，MT表达中明显的组织特异性可能会被高估。长期给予膳食镉后，组织MT浓度的变异性最好通过考虑组织中的镉、锌和铜，而非仅考虑组织镉来解释。
